Patterns in plant community assembly

群落生态学的中心目标是解释自然群落在组成上变化的实质程度。例如，植物群落在寄主物种的数量、群落资源如何在常驻物种之间分配以及组成物种的形态上都有所不同。虽然在理解驱动这种变化的机制方面已经付出了相当大的努力，但许多问题仍未解决，许多相互竞争的理论仍在激烈辩论中。例如，很明显，竞争在植物群落中起着重要作用；然而，目前的竞争模型表明，除了最具竞争力的物种外，竞争将导致所有物种被排除在外。考虑到几乎所有的自然群落都包含一个以上的物种，有理由认为，要么竞争的影响被其他促进多样性的过程所减轻，比如分散，要么竞争过程比我们所知道的要复杂得多，而且往往不会导致除了最具竞争力的物种之外的所有物种的消失。我和我的学生将通过开发更现实的多物种竞争模型来研究这些可能性，用可操作的现场实验来测试这些模型，并通过使用零建模技术来识别和量化竞争、分散和食草性对自然群落跨越重要环境梯度的影响。这项工作将有助于越来越多的关于这些重要机制如何相互作用以形成自然群落的文献。此外，了解可能增加（如扩散）或减少多样性（如竞争）的不同机制的相对影响将极大地为保护和恢复计划提供信息，并有助于入侵物种的管理。

The central goal of community ecology is to explain the substantial degree to which natural communities vary in composition. Plant communities, for example, vary in the number of species they host, how community resources are divided among resident species, and in the morphology of constituent species. While considerable effort has gone into understanding the mechanisms that drive this variation, many questions are still unresolved, and many competing theories are still vigorously debated. For example, it is clear that competition plays an important role in plant communities; however, current models of competition suggest that competition will result in the exclusion of all but the most competitive species. Given that virtually all natural communities contain more than one species, it stands to reason that either the impact of competition is mitigated by other processes that promote diversity, such as dispersal, or that the competitive process is more complicated than we know, and tends not to result in the loss of all but the most competitive species. My students and I will examine these possibilities by developing more realistic models of multi-species competition, testing these models with manipulative field experiments, and by using null modeling techniques to identify and quantify the impacts of competition, dispersal, and herbivory in natural communities spanning important environmental gradients. This work will contribute to the growing body of literature concerning how these important mechanisms interact to shape natural communities. Additionally, understanding the relative impact of different mechanisms that may augment (e.g., dispersal), or reduce diversity (e.g., competition) will greatly inform conservation and restoration initiatives, and aid in the management of invasive species.